Climate change and global warming are key issues. Consequently, a requirement exists to supervise energy consumption. Currently, in a standard household, electricity metering is done by a single meter which measures the sum of the energy consumption of all energy consuming devices in the household. The purpose of measuring the total energy consumption is to know how much to bill the consumer.
U.S. Pat. No. 5,572,438 discloses an energy management and building automation system including a local area network or home automation data bus. Each load (energy consuming device) is connected to the bus via a control module which may contain a circuit breaker to disconnect the load from the mains upon command or upon occurrence of a power outage. The control modules may be a current monitor control unit which measures load current, or a power monitor module which monitors the power consumed by the associated load. Both modules transmit bus messages indicating load status and status changes. The on/off status per load is determined by sampling the load current drawn by the load and comparing the sensed load current with a reference. If the current is below the reference, the load is considered to be switched off, if the current is above the reference, the load is considered to be switched on.
A first microcomputer is arranged preferably external to the premises and adjacent to the electric utility power meter. A second microcomputer preferably is inside the customer premises. The two microcomputers communicate with each other and with the various modules via the network/data bus. The first microcomputer communicates with the utility company via any appropriate communications link. The second microcomputer serves as in input/output terminal for the system, allowing the customer to set parameters and query the system as to power usage, displaying reports requested by the customer and messages transmitted by the utility company and by either microcomputer. The first microcomputer acts as a master controller and/or network server, communicating with the world outside the premises, as a communication gateway between voice, video and data services, and being the primary data collector and operator of load control modules. The utility company can access selected utilization data and control at least some loads via messages to the first microcomputer.